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Abstract:
During this period we concentrated our effort in two areas: (1) growth of epitaxial single-crystal beryllium films; and (2) multilayers and interfaces of material pairs incorporating 'new' materials for multilayer x-ray optics. To date we have succeeded in growing epitaxial single-crystal films of beryllium on alpha-AI2O3 (sapphire), silicon, and germanium using molecular beam epitaxy (MBE). This is a major development since beryllium is an excellent spacer for the difficult but desirable water window wavelengths (24 A < lambda < 44 A). To our knowledge, this is the first time beryllium has been grown epitaxially on any substrate. Our best quality beryllium films were grown on silicon. The ability to grow a single crystal layer of beryllium is a promising first step toward a beryllium-based single-crystal mirror. In the area of new material pairs. we began by using theoretical reflectivity calculations to assemble a list of promising new material pairs. We then prioritized this list by using what was already known about the materials, such as phase diagrams and diffusion studies. These materials pairs then were studied by sputtering and/or MBE.
| Limitations: |
 APPROVED FOR PUBLIC RELEASE |
| Description: |
Final rept. 1 Jan 90-28 Feb 93 |
| Pages: |
9 |
| Report Date: |
29 APR 93 |
| Contract Number: |
AFOSR-90-0140 |
| Report Number: |
A941762 |
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